Hoby Stefan, Mathis Alexander, Doherr Marcus G, Robert Nadia, Ryser-Degiorgis Marie-Pierre
Centre for Fish and Wildlife Health, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
J Wildl Dis. 2009 Jul;45(3):748-53. doi: 10.7589/0090-3558-45.3.748.
Five cases of fatal babesiosis in free-ranging chamois (Rupicapra r. rupicapra) attributed to infections with Babesia capreoli were recently recorded in two regions of the Swiss Alps. To investigate the ecologic factors that possibly lead to those fatal B. capreoli infections in chamois, blood, ticks, and demographic data of 46 roe deer (Capreolus c. capreolus), 48 chamois, and nine red deer (Cervus elaphus) were collected in 2006 and 2007 in both affected regions. Whereas no parasitic inclusions were found by microscopical examination of blood smears, B. capreoli was identified by polymerase chain reaction/sequencing in blood of 12 roe deer (26%, 95% confidence interval [CI]: 14.3-41.1), one chamois (2%, CI: 0-6.1), and one red deer (11%, CI: 0.3-48.2). Prevalence of B. capreoli was significantly higher in roe deer compared with chamois (P<0.001). All 214 ticks were identified as Ixodes ricinus, and significantly more roe deer (63%, CI: 47.5-76.8) were infested compared with chamois (21%, CI: 10.5-35.0, P<0.001). Overall, prevalences of both tick infestation and Babesia infection increased significantly (P<0.001) with decreasing altitude, and Babesia-positive samples were detected significantly more often from animals with tick infestation compared with animals without ticks (P = 0.040). Our results indicate that roe deer may play an important reservoir role for B. capreoli. It is hypothesized that the expansion of the presumed vector I. ricinus to higher elevations and its increased abundance in overlapping habitats of roe deer and chamois may favor the spillover of B. capreoli from roe deer to chamois.
最近在瑞士阿尔卑斯山的两个地区记录了5例野生羚羊（岩羚羊指名亚种）因感染鹿巴贝斯虫而死亡的病例。为了调查可能导致这些野生羚羊感染致命鹿巴贝斯虫的生态因素，2006年和2007年在两个受影响地区收集了46只狍（狍指名亚种）、48只野生羚羊和9只马鹿（马鹿）的血液、蜱虫及种群数据。虽然通过血液涂片显微镜检查未发现寄生虫包涵体，但通过聚合酶链反应/测序在12只狍（26%，95%置信区间[CI]：14.3 - 41.1）、1只野生羚羊（2%，CI：0 - 6.1）和1只马鹿（11%，CI：0.3 - 48.2）的血液中鉴定出了鹿巴贝斯虫。狍中鹿巴贝斯虫的患病率显著高于野生羚羊（P<0.001）。所有214只蜱均被鉴定为蓖麻硬蜱，与野生羚羊（21%，CI：10.5 - 35.0）相比，感染蜱的狍明显更多（63%，CI：47.5 - 76.8，P<0.001）。总体而言，蜱感染率和巴贝斯虫感染率均随海拔降低而显著增加（P<0.001），与未感染蜱的动物相比，感染蜱的动物检测到巴贝斯虫阳性样本的频率明显更高（P = 0.040）。我们的结果表明，狍可能在鹿巴贝斯虫的传播中起重要的宿主作用。据推测，假定的传播媒介蓖麻硬蜱向更高海拔地区的扩张及其在狍和野生羚羊重叠栖息地中数量的增加，可能有利于鹿巴贝斯虫从狍传播到野生羚羊。
